I started listening to K-pop a few years ago. I'm not a huge music person and it's whatever song I come across on YouTube that I like that I keep listening to.
I started off with H.O.T. (High Five of Teenagers) and G.O.D. (Groove Over Dose) and a little bit of S.E.S. I remember my sibling had a poster of HOT or GOD and a CD of SES so that's how I remembered/found them. XD
I loveee Candy by H.O.T.

I started listening to Big Bang a year ago and they're really good too! :'D

But I'm more into K-rap than K-pop. The usual K-pop is always girl groups and they're whatever.. /: It's usually I find 1 or a few songs I like then the rest of their songs I don't like, but that's how I am with a lot of artists & bands & groups.
I especially hate it when the girl rapper in the K-pop girl group raps and they always make their voice so ugly.. They put on like a low monotone serious rap voice? I prefer their normal/singing voice wayy more. It's like they're trying to sound so hard and serious? Doesn't work for me.